So I reviewed previous posts for a 5.9L that overheats in stop & go traffic but not on the HWY. Initially, temp needle was between 1/2-3/4 on gauge on 90'F day. I will not drive it in outside air temps higher than that for fear of warping the heads.

Water pump is flowing. Checked flow with radiator cap off.

I noticed the E-fan was not running with the A/C on. I swapped the engine relay and A/C fan relay & checked the fuse, both are ok.

I suspect the E-fan motor or the E-fan on/off switch does not work.

My question is, how can I check the E-fan motor and switch?

 

jump 12v to the fan leads, if it comes on its the switch, the relay or a connection, if it doesnt come on then its the fan motor is dead

also turn the a/c on and see if it comes on, if not put a multi-meter on the plug to see if you are getting the required voltage (12v)

 

Thanks buddy,

I found the fan disconnect at the bottom of the radiator and put a 20vdc meter to the switch side. It read 13.8vdc with the switch on and off.


My last question would be, what else would send a signal for the fan to run? Would it be a radiator temp sensor?

Jumpered from the battery to the fan and it would not go roundy, roundy. So, I believe that I have found the problem, thanks to your help.

 

Nope, one more question.

How difficult is it to replce the fan?

 

Dodge like to use the negative as the switch and even reverse polarity.

Anyway, sounds like a fan because you jumped it and nothing. You should be able to just replace the fan motor. It is easier to pull the fan clutch to give you access but you also could move the fan shroud to get to it as well. It's a fairly easy repair.

 

Thank You Gentleman.

You're input is greatly appreciated.